Dispersion Curves and Fields for a Chiral Negative Refraction Parallel-Plate Waveguide under PMC Boundary

The characteristics of a chiral negative refraction parallel-plate waveguide under PMC boundary are studied theoretically, and the corresponding dispersion relations, cut-off frequencies, propagating guided modes are obtained. Some novel features are found, such as fundamental mode will be not exist only if the chirality parameter κ>1, in addition, the cutoff frequency is no longer the conventionally defined frequency when propagation constant is zero, but the least frequency that guided mode can still propagate. According to the relations between propagation constant β and wavenumbers k+,k-, the dispersion curves are divided into three regions , and the electromagnetic field components in the regions are analyzed in detail.